This invention relates to ball bearings and particularly to means for lubricating the same.
Obviously, the life of a bearing is directly related to the lubrication or lack of lubricaton of its wear surfaces. Typically, the cage for the balls is a disc-like element that spans the spherical balls and carries a plurality of pockets spacing each ball. This cage is normally restrained axially by the balls and radially by lands formed on the inner or outer races and occupies a relatively large portion of the space. Thus, not only is it difficult to lubricate from an external source, it restricts discharge of lubricant from the bearing interior.
For the purpose of this application, it is to be understood that the races are the inner surfaces that bear against the balls and are formed in the rings. Hereinafter, reference to the ring includes its race portion.
In a high speed bearing it is desirable to obtain positive lubrication to the cage-ring interface as well as providing an adequate flow of lubricant to the interior of the bearings. Heretofore, a conventional method of obtaining adequate lubrication of the cage-ring interface was to provide separate lubricant passages in the inner ring.
I have found that by providing a cage formed into a scalloped ring or disc-like element which rides on its inner diameter in a circumferential slot or channel formed in the inner split ring and providing lubricant passages formed in the inner ring terminating at the slot, the lubricant is admitted into the slot to provide good lubrication of the cage/ring interface, and passes between the side walls of the channel and cage where this lubricant is pumped from the channel to the balls and wear surfaces of the inner and outer races. Hence, the same lubricant is used to first lubricate the cage-ring interface and then lubricate the balls and rings. This invention contemplates free discharge of lubricant from the bearing through the radial spaces between inner and outer rings.
Hence, the cage is restrained axially and radially by the inner ring. It has minimum mass and provides positive flow of lubricant to and unrestrictive flow from the bearing interior. Additionally, it permits minimal spacing of balls or maximum space for ball excursion with a given ball complement.